In a level, constant-altitude banked turn, if airspeed increases while bank angle remains the same, what happens to the load factor and turn radius?

In a level, constant-altitude banked turn, if airspeed increases while bank angle remains the same, what happens to the load factor and turn radius?

• A. Load factor increases and radius increases
• B. Load factor decreases and radius increases
• C. Load factor remains the same and radius increases
• D. Load factor remains the same and radius decreases

Answer: (C)

In a level, constant-altitude banked turn, the load factor is determined by how much lift is needed to balance weight with the bank angle, not by how fast you’re going. For a given bank angle, the vertical component of lift must equal weight, so L cos φ = W, which makes L = W / cos φ. The load factor n is L / W, so n = 1 / cos φ. That depends only on the bank angle and stays the same as airspeed changes. The turn radius, however, is tied to how much centripetal acceleration you need, which grows with speed. The horizontal component of lift provides that centripetal force: L sin φ = m v^2 / r. With L = W / cos φ, you get r = v^2 / (g tan φ). So increasing speed while keeping the bank angle fixed increases the turn radius. Therefore, the load factor remains the same and the radius increases.

In a level, constant-altitude banked turn, the load factor is determined by how much lift is needed to balance weight with the bank angle, not by how fast you’re going. For a given bank angle, the vertical component of lift must equal weight, so L cos φ = W, which makes L = W / cos φ. The load factor n is L / W, so n = 1 / cos φ. That depends only on the bank angle and stays the same as airspeed changes.

The turn radius, however, is tied to how much centripetal acceleration you need, which grows with speed. The horizontal component of lift provides that centripetal force: L sin φ = m v^2 / r. With L = W / cos φ, you get r = v^2 / (g tan φ). So increasing speed while keeping the bank angle fixed increases the turn radius.

Therefore, the load factor remains the same and the radius increases.